Segment Information - Disaggregation of revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 298,504	$ 262,256
North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	211,250	176,846
Latin America [Member]
Disaggregation of Revenue [Line Items]
Revenues	14,134	23,992
EMEA [Member]
Disaggregation of Revenue [Line Items]
Revenues	48,587	40,220
Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Revenues	24,533	21,198
On-Premises Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	109,657	113,204
SaaS Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	73,709	63,369
Scores Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	115,138	85,683
Scores
Disaggregation of Revenue [Line Items]
Revenues	115,138	85,683
Scores | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	110,197	82,073
Scores | Latin America [Member]
Disaggregation of Revenue [Line Items]
Revenues	284	514
Scores | EMEA [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,538	1,534
Scores | Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Revenues	3,119	1,562
Scores | On-Premises Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	0	0
Scores | SaaS Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	0	0
Scores | Scores Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	115,138	85,683
Decision Management Software
Disaggregation of Revenue [Line Items]
Revenues	31,188	28,914
Decision Management Software | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	15,587	13,824
Decision Management Software | Latin America [Member]
Disaggregation of Revenue [Line Items]
Revenues	4,333	5,225
Decision Management Software | EMEA [Member]
Disaggregation of Revenue [Line Items]
Revenues	7,265	6,124
Decision Management Software | Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Revenues	4,003	3,741
Decision Management Software | On-Premises Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	23,679	23,609
Decision Management Software | SaaS Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	7,509	5,305
Decision Management Software | Scores Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	0	0
Applications
Disaggregation of Revenue [Line Items]
Revenues	152,178	147,659
Applications | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	85,466	80,949
Applications | Latin America [Member]
Disaggregation of Revenue [Line Items]
Revenues	9,517	18,253
Applications | EMEA [Member]
Disaggregation of Revenue [Line Items]
Revenues	39,784	32,562
Applications | Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Revenues	17,411	15,895
Applications | On-Premises Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	85,978	89,595
Applications | SaaS Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	66,200	58,064
Applications | Scores Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 0	$ 0
Revenue from Contract with Customer Benchmark [Member]
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	100.00%	100.00%
Revenue from Contract with Customer Benchmark [Member] | Scores
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	39.00%	33.00%
Revenue from Contract with Customer Benchmark [Member] | Decision Management Software
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	10.00%	11.00%
Revenue from Contract with Customer Benchmark [Member] | Applications
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	51.00%	56.00%